Hermosa Greenbelt Habitat Restoration Key for a Special South Bay Butterfly

Hermosa Greenbelt Habitat Restoration key for a special South Bay Butterfly

On June 1, 1976, the El Segundo blue butterfly was officially listed as an endangered

species. This determination meant that additional resources would be provided by the

US Fish and Wildlife Service to help the El Segundo blue butterfly increase its range

and population size.

While most people are familiar with monarch butterflies that migrate from the interior of

the USA to either Mexico or California through multiple generations, the El Segundo

blue ( Euphilotes allyni,) has a different life cycle approach. This butterfly is known as a

single-brood butterfly, meaning that it only reproduces once a year within a specific time

window. And to reproduce, it needs a specific plant, the sea-cliff buckwheat (Eriogonum

parvifolium), which grows on our local sand dunes and cliffs.

Loss of Habitat

The primary threats to the ESB are loss of habitat due to coastal development and

climate change. Changes in the host and nectar plants’ blooming season, which

determines the butterflies’ ability to reproduce, along with sea level rise that may

threaten the butterflies’ coastal habitat. By planting native gardens in urban spaces, we

can help connect habitat and support struggling species such as the El Segundo blue.

How the Hermosa Greenbelt Plays a Key Role

Habitat restoration and Greenbelt expansion will help the endangered E. allyni recover

and potentially thrive in their natural range. There is no other natural habitat corridor

between El Segundo and Redondo Beach. The South Bay Parkland Conservancy in

conjunction with the USFWS and the Cities of Redondo and Hermosa Beach are

diligently working to reconnect this critical and unique habitat that has been fragmented

for many decades, with the goal of mitigating habitat loss due in large part to the loss of

coastal dunes in Hermosa Beach.

Plant installations along the Redondo Beach Bluffs and Hermosa Greenbelt prioritize

the host plant Eriogonum parvifolium) . As these plants have been reintroduced along

their historic ranges, the butterflies have returned, including the endangered ESB, the

Acmon Blue (Plebejus acmon), and the threatened Monarch (Danaus plexippus). By

working towards reestablishing continuous habitat and interconnecting previously

isolated patches of vegetation, the range of the ESB may one day resemble what it was.

The inescapable conclusion is that the reestablishment of El Segundo Blue Butterfly

habitat provides the only path of connectivity for the smaller populations of butterfly

that are scattered from Ballona Wetlands through Malaga Cove, and this necessitates

a habitat corridor along the Greenbelt through the city of Hermosa Beach. The test plots

have demonstrated that a specific plant palette used by SBPC will thrive along the

Greenbelt as it does in Redondo and Torrance Beaches, increasing the chance of

project success and providing the endangered ESB with its best chance of survival. The

Hermosa community has rallied around this project, contributing more than a thousand

volunteer hours and planting nearly 3,000 plants in the last year and half. Together we

can make a difference and bring the El Segundo Blue butterfly from the brink of

extinction.

Anyone interested in supporting South Bay Parkland Conservancy or volunteering for

various restoration efforts in the South Bay please visit https://www.southbayparks.org.

Mary Simun

South Bay Parkland Conservancy, Biologist and Educational Director

February 2024